Push-ups are an activity which were gauged, the power output is a downstream analysis.
Totally ignoring 2/3rds of the result of a quoted paper (the author could have emphasised the caveat you quoted if she wanted to keep her critical review ideologically pure), and mixing up the numbers for the 1/3rd that is quoted, is not good.
e - fyi, MDPI journals have a
shady reputation with respect to peer review.
can confirm with first-hand experience too: 3 papers from my phd, one spent a year in review, one spent 2 months (both needed substantial revisions), and the one sent to an MDPI journal took 2 weeks with very minor changes.
doesn't mean this article is crap, but combined with the sloppy citation, it just increases suspicion.